A local gun shop in Austin has also started accepting Bitcoins. Michael Cargill, owner of Central Texas Gun Works, said he's processed twenty Bitcoin transactions since January.

Cargill echoed Schauble's point about anonymous buyers. "They still have to go into our gun store, or the gun store that we ship to, and you still have to do the background check," said Cargill.

TrackingPoint and Central Texas Gun Works both handle payments through Coinvoice, a Bitcoin e-commerce processor. Coinvoice immediately converts clients' Bitcoins into dollars, which reduces the risk of being exposed to the volatile currency. Bitcoin is a relatively new currency that can rarely be used to pay suppliers. Plus, its value fluctuates wildly. In recent months, the value of one Bitcoin has ranged from $500 to $1,100.

Jake Yocom-Piatt, CEO of Conformal Systems, which runs Coinvoice, said companies rely entirely on banks to process Bitcoin transactions, but that some banks refuse to process the back end of a gun purchase made with Bitcoin. He adds that the bank Coinvoice works with is the rare exception.